Display device including display panel using AC discharge

Abstract

A wall-voltage generation period is provided once in every several tens or hundreds of frames. A wall voltage (broken line) generated in the wall-voltage generation period does no disappear irrespective of the presence or absence of discharge emission. The presence or absence of discharge emission is controlled by varying the baseline of a voltage across electrodes (solid line) depending on variations in an address voltage (Va) during a display period. The number of priming reset discharges which has been necessary at least once in each frame can be reduced.

What is claimed is:  
     
       1. A display device comprising: 
       a display panel using AC discharge; and  
       a driving circuit, wherein  
       said display panel includes a discharge cell provided with a first electrode and a second electrode covered with a dielectric, said first and second electrodes being connected to said driving circuit and said driving circuit being configured to apply voltages to said first and second electrodes including a sustain voltage applied to said first electrode in the presence of a wall voltage stored by said discharge cell to cause light emission from said discharge cell by inducing AC gas discharge,  
       said driving circuit being further configured to apply voltages across said first and second electrodes to prevent said AC gas discharge light emission from occurring in said discharge cell without erasing said wall voltage, even if said sustain voltage is applied to said first electrode.  
     
     
       2. The display device according to claim  1 , wherein said driving circuit is further configured to initially provide said wall voltage stored by said discharge cell by applying a voltage higher than a firing voltage across said first and second electrodes once in a predetermined number of displayed frames. 
     
     
       3. The display device according to claim  2 , wherein said wall voltage stored by said discharge cell results from said driving circuit applying a single voltage pulse which changes gently from a peak value to a baseline. 
     
     
       4. The display device according to claim  2 , wherein said wall voltage stored by said discharge cell results from said driving circuit applying a first voltage pulse having a voltage higher than said firing voltage and a second bipolar voltage pulse which is applied by said driving circuit following said first voltage pulse, with said second bipolar voltage pulse having an amplitude lower than said first voltage pulse. 
     
     
       5. The display device according to claim  1 , wherein said driving circuit is further configured to switch between causing said AC gas discharge light emission and preventing said AC gas discharge light emission by shifting a baseline of a bipolar voltage pulse which is applied across said first and second electrodes. 
     
     
       6. The display device according to claim  5 , wherein said driving circuit is further configured to apply voltages to prevent said AC gas discharge light emission for a period of time about an integral multiple of a cycle of said bipolar voltage pulse. 
     
     
       7. The display device according to claim  6 , wherein said driving circuit is further configured to apply voltages to start a condition where said baseline is shifted by a predetermined value between a end of a voltage pulse of one polarity and a beginning of a voltage pulse of opposite polarity, and after said period of time, terminating said condition between said end of a voltage pulse of one polarity and said beginning of a voltage pulse of said opposite polarity, with said voltage pulse of one polarity and said voltage pulse of said opposite polarity constituting said bipolar voltage pulse. 
     
     
       8. The display device according to claim  6 , wherein said driving circuit is further configured to apply voltages varying said baseline so that a baseline of a voltage pulse of one polarity takes a first value and a baseline of a voltage pulse of opposite polarity takes a second value, with said voltage pulse of one polarity and said voltage pulse of said opposite polarity constituting said bipolar voltage pulse, and with said first and second values being set to minimize a difference between a maximum value and a minimum value of said bipolar voltage pulse. 
     
     
       9. The display device according to claim  8 , wherein said varying said baseline so that a baseline of a voltage pulse of one polarity takes a first value and a baseline of a voltage pulse of said opposite polarity takes a second value is performed between the end of a voltage pulse of one polarity and the beginning of a voltage pulse of said opposite polarity. 
     
     
       10. A display device according to claim  5 , wherein said driving circuit is further configured to apply voltages so that said baseline is shifted by varying a voltage applied to either of said first and second electrodes. 
     
     
       11. The display device according to claim  5 , wherein said driving circuit is further configured to apply voltages so that said baseline is shifted by varying voltages applied to said first and second electrodes. 
     
     
       12. The display device according to claim  11 , wherein said driving circuit is further configured to apply voltages so that a voltage applied to said second electrode varies, during the prevention of said AC gas discharge light emission and a voltage applied to said first electrode is varied by a corresponding amount. 
     
     
       13. The display device according to claim  12 , wherein said driving circuit is further configured to apply voltages so that a baseline of the amplitude of said wall voltage is reset to 0V. 
     
     
       14. The display device according to claim  12 , wherein said driving circuit is further configured to apply voltages so that said sustain voltage is applied to said first electrode which is provided in common to a plurality of discharge cells. 
     
     
       15. A method of driving a display panel using ac discharge which includes a discharge cell provided with a first electrode and a second electrode covered with a dielectric and causing light emission from said discharge cell by inducing ac gas discharge by said first and second electrodes, 
       said method comprising the steps of:  
       (a) causing a discharge emission in said discharge cell by applying a sustain voltage to said first electrode by the use of a wall voltage generated in said discharge cell; and  
       (b) preventing said discharge emission from occurring in said discharge cell without erasing said wall voltage, even if said sustain voltage is applied to said first electrode.